A primary battery for efficient cadmium contamination remediation and electricity generation.

In this work, two kinds of primary batteries, both of which included a Zn anode, C rod cathode, copper wire and electrolyte composed of Cd-contaminated water or soil, were constructed in the first attempt to both remove Cd and generate electricity. Unlike traditional technologies such as electrokinetic remediation with high energy consumption, this technology could realize Cd migration to aggregation and solidification and generate energy at the same time through simultaneous galvanic reactions. The passive surface of Zn and C was proven via electrochemical measurements to be porous to maintain the relatively active galvanic reactions for continuous Cd precipitation. Cd RE (removal efficiency) and electricity generation were investigated under different conditions, based on which two empirical models were established to predict them successfully. In soil, KCl was added to desorb Cd from soil colloids to promote Cd removal. These systems were also proven to remove Cd efficiently when their effects on plants, zebrafish, and the soil bacterial community were tested. LEDs could be lit for days by utilizing the electricity produced herein. This work provides a novel, green, and low-cost route to remediate Cd contamination and generate electricity simultaneously, which is of extensive practical significance in the environmental and energy fields.